Natural H₂ in Kansas: Deep or shallow origin?

Abstract

Key Points: A new well provide the opportunity of a reappraisal of a persistent regional H 2 production in intracontiental settings, in Kansas. Two different origins are suggested for H 2 production in intra-cratonic context: a crustal origin, a surficial origin. Hypotheses of two H 2 are supported by geochemical properties of associated gases, by water associated and completion story of the well.2 AbstractA geochemical study of gas coming from three wells in northeastern Kansas supplements previous studies from the 1980s and points to a persistent regional phenomenon of H 2 production. In 2008, a new well showed, just after drilling, a dry gas phase with more than 80 mole % of H 2 , followed by a water production associated with gas. This gas is mainly composed of N 2 , He, H 2 and occasionally CH 4 , with changing proportions through time. A drastic decrease in H 2 at the well was observed since the aquifer is produced, along with occasional recharges in H 2 evidenced notably in the early phases of gas sampling. We demonstrate that this evolution of gas composition is closely associated to the well completion story. Accordingly, two distinct origins of H 2 are proposed: (1) water reduction associated to iron oxidation in the Precambrian basement (deep crustal H 2 ); (2) reactions occurring in the tubing, primarily attributed to a high Fe 2+ content and organic carbon (DOC=4.1 mg.L -1 ) dissolved in the water. The low δD values averaging -760 ‰ are attributed to low temperature processes, in agreement with both the hypothesis. Furthermore, the suggested origins are supported by the observed gas associations: (a) deep crustal H 2 with radiogenic gases ( 4 He and 40 Ar) and metamorphic N 2 ( 15 N averaging +2.5‰); (b) surficial H 2 with methane produced in the sedimentary aquifer and the tubing by methanogenic organisms.

What Pulsating H2 Emissions Suggest about the H2 Resource in the Sao Francisco Basin of Brazil

“…Since the gas flux is linear, we can add the deep H 2 -bearing gas flux, V deep , to (6) to obtain the total gas flux, V total Z=0 (t):…”

Natural hydrogen continuous emission from sedimentary basins: The example of a Brazilian H2-emitting structure

“…Geologists have recently investigated natural hydrogen sources and whether they could be naturally produced [36]. Unexpectedly, the occurrence of hydrogen in continental shallow wells has been noted, as in Mali while drilling for water [37], in oil an gas exploration in Kansas, USA [13] or in basement rocks mines [30,44]. Monitoring of H 2 -enriched natural gases leaking from mines long existed in the Kola Peninsula in Russia to prevent accidents from happening, as such gas mixture is easily combustible and explosive [29,30].…”

Reduced gas seepages in ophiolitic complexes: Evidences for multiple origins of the H2-CH4-N2 gas mixtures

“…This is notably the case of the famous Chimaera near Antalya, place of the first Olympic flame, which are known to be burning since antiquity (De Boer et al, 2007;Hosgörmez et al, 2007Hosgörmez et al, , 2008 and the site of "Los Fuegos Eternos" in the Philippines known since the Spanish colonization (Abrajano et al, 1988(Abrajano et al, , 1990. H 2 -bearing gases discovered in ophiolitic rocks onshore show lower contents in helium than those discovered in terrestrial context in non-ophiolitic rocks (Coveney et al, 1987;Ikorsky et al, 1999;Sherwood-Lollar et al, 2007;Larin et al, 2015;Zgonnik et al, 2015;Guélard et al, 2017).…”